1. Field of the Invention
The present invention pertains to methods for treating ras-mediated proliferative disorders in a mammal using reovirus.
2. References
The following publications, patent applications and patents are cited in this application:    U.S. Pat. No. 5,023,252    Armstrong, G. D. et al. (1984), Virology 138:37;    Aronheim, A., et al., (1994) Cell, 78:949-961    Barbacid, M., Annu. Rev. Biochem., 56:779-827 (1987);    Berrozpe, G., et al. (1994), Int. J. Cancer, 58:185-191    Bischoff, J. R. and Samuel, C. E., (1989) Virology, 172:106-115    Cahill, M. A., et al., Curr. Biol., 6:16-19 (1996);    Chandron and Nibert, “Protease cleavage of reovirus capsid protein mu1 and mu1C is blocked by alkyl sulfate detergents, yielding a new type of infectious subvirion particle”, J. of Virology 72 (1):467-75 (1998    Chaubert, P. et al. (1994), Am. J. Path. 144:767; Bos, J. (1989) Cancer Res. 49:4682.    Cuff et al., “Enteric reovirus infection as a probe to study immunotoxicity of the gastrointestinal tract” Toxicological Sciences 42 (2):99-108 (1998)    Der, S. D. et al., Proc. Natl. Acad. Sci. USA 94:3279-3283 (1997)    Dudley, D. T. et al., Proc. Natl. Acad. Sci. USA 92:7686-7689 (1995)    Duncan et al., “Conformational and functional analysis of the C-terminal globular head of the reovirus cell attachment protein” Virology 182 (2):810-9 (1991)    Fields, B. N. et al. (1996), Fundamental Virology, 3rd Edition, Lippincott-Raven;    Gentsch, J. R. K. and Pacitti, A. F. (1985), J. Virol. 56:356;    E. Harlow and D. Lane, “Antibodies: A laboratory manual”, Cold Spring Harbor Laboratory (1988)    Helbing, C. C. et al., Cancer Res. 57:1255-1258 (1997)    Hu, Y. and Conway, T. W. (1993), J. Interferon Res., 13:323-328    Laemmli, U. K., (1970) Nature, 227:680-685    Lee. J. M. et al. (1993) PNAS 90:5742-5746;    Lee, P. W. K. et al. (1981) Virology, 108:134-146    Levitzki, A. (1994) Eur. J. Biochem. 226:1; James, P. W., et al. (1994) Oncogene 9:3601; Bos, J. (1989) Cancer Res. 49:4682    Lowe. S. W. et al. (1994) Science, 266:807-810;    Lyon, H., Cell Biology, A Laboratory Handbook, J. E. Celis, ed. Academic Press. 1994, p. 232    Mah et al., “The N-terminal quarter of reovirus cell attachment protein sigma 1 possesses intrinsic virion-anchoring function” Virology 179 (1):95-103 (1990)    McRae, M. A. and Joklik, W. K., (1978) Virology, 89:578-593    Millis, N E et al. (1995) Cancer Res. 55:1444;    Mundschau, L. J. and Faller, D. V., (1992) J. Biol. Chem., 267:23092-23098    Nagata, L., et al., (1984) Nucleic Acids Res., 12:8699-8710    Paul R. W. et al. (1989) Virology 172:382-385    Raybaud-Diogene. H. et al. (1997) J. Clin. Oncology, 15 (3):1030-1038;    Remington's Pharmaceutical Sciences, Mace Publishing Company, Philadelphia Pa. 17th ed. (1985)    Robinson, M. J. and Cobb, M. H., Curr. Opin. Cell. Biol. 9:180-186 (1997);    Rosen, L. (1960) Am. J. Hyg. 71:242;    Sabin, A. B. (1959), Science 130:966    Samuel, C. E. and Brody, M., (1990) Virology, 176:106-113;    Smith, R. E. et al., (1969) Virology, 39:791-800    Stanley, N. F. (1967) Br. Med. Bull. 23:150    Strong, J. E. et al., (1993) Virology, 197:405-411;    Strong, J. E. and Lee, P. W. K., (1996) J. Virol., 70:612-616    Trimble, W. S. et al. (1986) Nature, 321:782-784    Turner and Duncan, “Site directed mutagenesis of the C-terminal portion of reovirus protein sigma1: evidence for a conformation-dependent receptor binding domain” Virology 186 (1):219-27 (1992);    Waters, S. D. et al., J. Biol. Chem. 270:20883-20886 (1995)    Wiessmuller, L. and Wittinghofer, F. (1994), Cellular Signaling 6 (3):247-267;    Wong, H., et al., (1994) Anal. Biochem., 223:251-258    Yang, Y. L. et al. EMBO J. 14:6095-6106 (1995)    Yu, D. et al. (1996) Oncogene 13:1359
All of the above publications, patent applications and patents are herein incorporated by reference in their entirety to the same extent as if each individual publication, patent application or patent was specifically and individually indicated to be incorporated by reference in its entirety.
3. State of the Art
Normal cell proliferation is regulated by a balance between growth-promoting proto-oncogenes and growth-constraining tumor-suppressor genes. Tumorigenesis can be caused by genetic alterations to the genome that result in the mutation of those cellular elements that govern the interpretation of cellular signals, such as potentiation of proto-oncogene activity or inactivation of tumor suppression. It is believed that the interpretation of these signals ultimately influences the growth and differentiation of a cell, and that misinterpretation of these signals can result in neoplastic growth (neoplasia).
Genetic alteration of the proto-oncogene Ras is believed to contribute to approximately 30% of all human tumors (Wiessmuller, L. and Wittinghofer, F. (1994), Cellular Signaling 6 (3):247-267; Barbacid, M. (1987) A Rev. Biochem. 56, 779-827). The role that Ras plays in the pathogenesis of human tumors is specific to the type of tumor. Activating mutations in Ras itself are found in most types of human malignancies, and are highly represented in pancreatic cancer (80%), sporadic colorectal carcinomas (40-50%), human lung adenocarcinomas (15-24%). thyroid tumors (50%) and myeloid leukemia (30%) (Minis, N E et al. (1995) Cancer Res. 55:1444; Chaubert, P. et al. (1994), Am. J. Path. 144:767; Bos, J. (1989) Cancer Res. 49:4682). Ras activation is also demonstrated by upstream mitogenic signaling elements, notably by tyrosine receptor kinases (RTKs). These upstream elements, if amplified or overexpressed, ultimately result in elevated Ras activity by the signal transduction activity of Ras. Examples of this include overexpression of PDGFR in certain forms of glioblastomas, as well as in c-erbB-2/neu in breast cancer (Levitzki, A. (1994) Eur. J. Biochem. 226:1; James, P. W., et al. (1994) Oncogene 9:3601; Bos, J. (1989) Cancer Res. 49:4682).
Current methods of treatment for neoplasia include surgery, chemotherapy and radiation. Surgery is typically used as the primary treatment for early stages of cancer; however, many tumors cannot be completely removed by surgical means. In addition, metastatic growth of neoplasms may prevent complete cure of cancer by surgery. Chemotherapy involves administration of compounds having antitumor activity, such as alkylating agents, antimetabolites, and antitumor, antibiotics. The efficacy of chemotherapy is often limited by severe side effects, including nausea and vomiting, bone marrow depression, renal damage, and central nervous system depression. Radiation therapy relies on the greater ability of normal cells, in contrast with neoplastic cells, to repair themselves after treatment with radiation. Radiotherapy cannot be used to treat many neoplasms, however, because of the sensitivity of tissue surrounding the tumor. In addition, certain tumors have demonstrated resistance to radiotherapy and such may be dependent on oncogene or anti-oncogene status of the cell (Lee. J. M. et al. (1993) PNAS 90:5742-5746; Lowe. S. W. et al. (1994) Science, 266:807-810; Raybaud-Diogene. H. et al. (1997) J. Clin. Oncology, 15 (3):1030-1038). In view of the drawbacks associated with the current means for treating neoplastic growth, the need still exists for improved methods for the treatment of most types of cancers.